private static void EnsureLoading(ViewModelBase model, FrameworkElement view)
{
Preconditions.CheckArgumentNotNull(model, "model");
Preconditions.CheckArgumentNotNull(view, "view");
Interactivity.TriggerCollection triggers = Interactivity.Interaction.GetTriggers(view);
Ensure(triggers, view, LoadedEventName, ViewModelBase.LoadMethodName);
Ensure(triggers, view, UnloadedEventName, ViewModelBase.UnloadMethodName);
}
private static void Ensure(Interactivity.TriggerCollection triggers, DependencyObject view, string eventName, string methodName)
{
if (IsEnsured(triggers, eventName, methodName))
{
return; // already ensured
}
string binding = string.Format("[{0}] = [{1}()]", eventName, methodName);
triggers.Add(Parser.Parse(view, binding).Single());
}
private static bool IsEnsured(Interactivity.TriggerCollection triggers, string eventName, string methodName)
{
Interactivity.EventTrigger trigger = triggers.OfType <Interactivity.EventTrigger>().FirstOrDefault(a => a.EventName == eventName);
if (trigger == null)
{
return(false);
}
else
{
return(trigger.Actions.OfType <ActionMessage>().Any(a => a.MethodName == methodName && a.Parameters.Count == 0));
}
}
